Amazon EKS Architecture Diagram: Complete Guide to Production Kubernetes on AWS

What Is Amazon EKS?

Amazon Elastic Kubernetes Service (EKS) is a fully managed Kubernetes service that simplifies running Kubernetes on AWS without needing to install or operate your own control plane. AWS manages the Kubernetes control plane across multiple Availability Zones for high availability, while you manage the worker nodes that run your workloads.

EKS provides deep integration with AWS services including IAM, VPC, security groups, and load balancers, making it the preferred choice for organizations that want to run Kubernetes with AWS-native capabilities.

High-Level EKS Architecture

At the highest level, an EKS cluster consists of two major layers:

1. Control Plane – Fully managed by AWS
2. Worker Nodes – Run inside your AWS account (EC2 instances or Fargate)

Both layers operate inside your VPC, communicate via the AWS VPC CNI plugin, and are secured through IAM roles and Kubernetes RBAC.

┌─────────────────────────────────────────────────────────────────────────────┐
│                           AWS Managed Control Plane                        │
│  ┌───────────────────────────────────────────────────────────────────────┐ │
│  │  • API Server (Public + Private Endpoints)                           │ │
│  │  • etcd (Multi-AZ replicated)                                        │ │
│  │  • Scheduler                                                         │ │
│  │  • Controller Manager                                                │ │
│  │  • Cloud Controller Manager (AWS integrations)                      │ │
│  └───────────────────────────────────────────────────────────────────────┘ │
│                                    │                                        │
│                     Secure ENI Connection (cross-account)                   │
│                                    ▼                                        │
└─────────────────────────────────────────────────────────────────────────────┘
                                     │
                                     ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                              Your VPC                                       │
│  ┌───────────────────────────────────────────────────────────────────────┐ │
│  │                    Public Subnets (ALB, NAT Gateways)                  │ │
│  └───────────────────────────────────────────────────────────────────────┘ │
│  ┌───────────────────────────────────────────────────────────────────────┐ │
│  │                    Private Subnets (Worker Nodes)                     │ │
│  │  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐                   │ │
│  │  │ Worker Node │  │ Worker Node │  │ Worker Node │                   │ │
│  │  │  (EC2)      │  │  (EC2)      │  │  (EC2)      │                   │ │
│  │  │  ┌───────┐  │  │  ┌───────┐  │  │  ┌───────┐  │                   │ │
│  │  │  │ Pod A │  │  │  │ Pod B │  │  │  │ Pod C │  │                   │ │
│  │  │  └───────┘  │  │  └───────┘  │  │  └───────┘  │                   │ │
│  │  └─────────────┘  └─────────────┘  └─────────────┘                   │ │
│  └───────────────────────────────────────────────────────────────────────┘ │
│                                                                             │
│  ┌───────────────────────────────────────────────────────────────────────┐ │
│  │                    Data Plane Services                                 │ │
│  │  • Amazon EBS (persistent volumes)   • Amazon EFS (shared storage)    │ │
│  │  • Amazon S3 (object storage)        • Amazon RDS (databases)         │ │
│  └───────────────────────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────────────────────┘

Component 1: EKS Control Plane (Managed by AWS)

The EKS control plane is the brain of your Kubernetes cluster, entirely managed by AWS. It runs across three Availability Zones by default, providing automatic high availability.

Control Plane Components

Kubernetes API Server – The only entry point for all cluster operations. Handles kubectl requests, scheduling instructions, and cluster state changes. API server endpoints are behind a Network Load Balancer.

etcd – A highly available, multi-AZ replicated key-value store that holds all cluster state: pod configs, secrets, services, and deployment metadata. EKS provides a managed etcd that is automatically replicated across three AZs.

Scheduler – Places pods on available worker nodes based on capacity, taints/tolerations, and affinity rules.

Controller Manager – Runs controllers that manage deployments, replicas, node lifecycle, and service endpoints.

Cloud Controller Manager – Integrates with AWS services like ELB, EBS, and IAM.

What You Control vs. What AWS Controls

AWS manages the control plane entirely—you cannot SSH into it or modify it directly. AWS handles version upgrades, patching, availability, and scalability. What you control:

• API server endpoint access (public, private, or both)
• Kubernetes audit logging
• Add-on versions and configurations
• RBAC and admission control

Control Plane Connectivity

During control plane scaling or patching, API server IPs can change (DNS TTL is 60s). Kubernetes API consumers should implement DNS re-resolution and retries with backoff and jitter for transient failures.

Component 2: Worker Nodes (Data Plane)

Worker nodes run your actual application workloads. EKS supports three primary options for worker nodes:

Option A: EKS Managed Node Groups (MNG)

AWS manages the EC2 instances in an Auto Scaling group, including AMI updates and node health. This is the recommended approach for most production workloads.

Best for: Stable, predictable workloads where you want AWS to handle node lifecycle management.

Option B: Karpenter

An open-source, flexible Kubernetes-native cluster autoscaler that provisions nodes dynamically based on pod scheduling requirements. Launches instances directly, with fast scaling and native Spot support.

Best for: Dynamic, varied workloads requiring fast, flexible scaling.

Option C: AWS Fargate

Serverless compute for Kubernetes. Each pod runs in its own isolated environment with per-pod billing and no infrastructure management.

Best for: Batch workloads, low-density workloads, and teams that want to eliminate node management entirely.

Option D: EKS Auto Mode

The newest option where AWS fully manages the node lifecycle—provisioning, scaling, OS updates, and security patches.

Best for: Teams that want minimal operational overhead for standard workloads.

Option E: Self-Managed Nodes

You deploy and manage your own EC2 Auto Scaling groups and AMIs.

Best for: Custom AMI/kernel requirements or specialized use cases.

Node Components

Each worker node runs:

• Kubelet – Communicates with the API server
• Container Runtime – containerd or Docker
• Amazon VPC CNI Plugin – Manages pod networking

Component 3: VPC Networking

All EKS resources are deployed in a VPC within your AWS account. The VPC and subnets must be tagged appropriately so Kubernetes can use them for deploying resources like load balancers.

Subnet Configuration

A standard production EKS architecture distributes subnets across three Availability Zones:

• Public Subnets: Host internet-facing resources (ALB, NAT Gateways). Must be configured to auto-assign public IP addresses for EC2 instances.
• Private Subnets: Host worker nodes and application pods. If private subnets lack internet access, pods must be able to access AWS services like Amazon ECR through VPC endpoints.

VPC CNI Plugin

Each pod receives an IP address from your VPC subnet via an Elastic Network Interface (ENI). This provides:

• Native VPC networking for pods
• Direct communication with other AWS services
• No overlay network overhead

Security Groups

When you create a cluster, Amazon EKS creates a security group associated with both the cluster endpoint and all managed nodes. Additional security groups control inbound/outbound traffic.

The control plane and worker nodes must be able to communicate over all ports through appropriately tagged security groups.

Load Balancers

EKS automatically provisions load balancers for services:

• Network Load Balancer (NLB): For internal TCP/UDP services
• Application Load Balancer (ALB): For HTTP/HTTPS ingress (via AWS Load Balancer Controller)

Component 4: IAM and Security

IAM Integration

EKS integrates IAM roles with Kubernetes service accounts via IRSA (IAM Roles for Service Accounts). This allows pods to assume IAM roles and access AWS services with least-privilege permissions.

Security Layers

API Server Access

For production, AWS recommends private-only or private + public endpoint access. Public-only is not recommended for production environments.

Component 5: Storage

Pods are ephemeral—stateful applications require persistent storage.

Component 6: Monitoring and Scaling

Monitoring

Scaling

EKS Deployment Models

Production Best Practices

Control Plane Reliability

• Use informers/watches instead of polling LIST calls against the API server
• Set appropriate QPS and burst limits on controllers
• Enable API Priority and Fairness (APF) for throttling
• Monitor etcd database size—when exceeded, the cluster becomes read-only
• Avoid "catch-all" admission webhooks that match all API groups and resources
• Set failurePolicy: Ignore with timeoutSeconds < 30 for webhooks

Data Plane Reliability

• Deploy across multiple Availability Zones for high availability
• Use Pod Disruption Budgets to ensure minimum availability during voluntary disruptions
• Configure health probes (readiness, liveness, startup)
• Set resource limits to prevent noisy neighbors
• Use topology spread constraints to distribute pods across failure domains

Scaling Considerations

• Avoid scaling spikes that increase cluster size by more than ~10% at a time (e.g., 1,000 to 1,100 nodes)
• The control plane auto-scales but needs time to adapt

Network Policies

Implement network segmentation and tenant isolation using network policies. Network policies are similar to AWS security groups—you create ingress and egress rules and assign them to pods using pod selectors and labels.

When to Use EKS vs. Alternatives

Tools for Creating EKS Architecture Diagrams

You can create professional EKS architecture diagrams using:

Manual Tools:

• Draw.io (diagrams.net): Free, browser-based, includes AWS icon libraries
• Lucidchart: Collaborative diagramming with AWS templates

AI-Powered Tools:

AI Line Studio generates AWS architecture diagrams from natural language descriptions in 15–20 seconds. For AWS-specific workflows, the dedicated AI cloud diagram generator turns descriptions into production-ready visuals. The AI architecture diagram builder helps build and refine EKS architecture diagrams into production-ready designs.

Infrastructure as Code:

Tools like Terraform and AWS CloudFormation can generate diagrams from your infrastructure code.

Summary

Amazon EKS is a fully managed Kubernetes service with a two-layer architecture: a highly available control plane managed by AWS and worker nodes running in your VPC. Key takeaways:

• Control Plane: Managed by AWS, runs across 3 AZs, includes API server, etcd, scheduler, and controllers
• Worker Nodes: Choose from Managed Node Groups, Karpenter, Fargate, Auto Mode, or self-managed
• Networking: VPC CNI gives each pod a VPC IP address; security groups control traffic
• IAM: IRSA maps IAM roles to Kubernetes service accounts
• Scaling: Cluster Autoscaler, HPA, and VPA handle different scaling dimensions
• Best Practices: Multi-AZ deployment, pod disruption budgets, health probes, and resource limits

To start building your own EKS architecture diagrams, explore the EKS AWS architecture diagram tool for templates and practical examples. For end-to-end system architecture beyond Kubernetes, the AI system architecture generator covers distributed and enterprise system designs.